This invention relates to a semiconductor processing apparatus and a diagnosis method for the apparatus. More particularly, the invention relates to a semiconductor processing apparatus capable of diagnosing an internal condition of a process chamber of a semiconductor processing apparatus and a diagnosis method for the apparatus.
Existing semiconductor processing apparatuses for processing a sample such as a semiconductor substrate include a plasma etching apparatus that utilizes reactive plasma, a plasma CVD (Chemical Vapor Deposition) apparatus and a thermal CVD apparatus that conducts a film formation process by exposing a semiconductor substrate held at a temperature suitable for the treatment into a reactive gas.
In the semiconductor processing apparatuses described above, reaction products formed during processing of the semiconductor substrate are deposited to an inner wall of a process chamber. When this deposit peels off from the process chamber inner wall, it forms particles with peel and the particles so formed fall and adhere to the surface of the semiconductor substrate. When the particles adhere to the substrate surface, they invite short-circuit or disconnection of wiring of an integrated circuit fabricated on the surface of the semiconductor substrate or remains of etching. In consequence, defects of the semiconductor devices as the product and the lowering of production yield occur.
To avoid the problem, dry cleaning such as gas cleaning conducted by filling a reactive gas while the internal pressure of the process chamber of the semiconductor processing apparatus is kept vacuum or plasma cleaning that uses reactive plasma is periodically conducted to remove the reaction byproducts.
To remove the deposit that cannot be removed by dry cleaning described above, a cleaning operation (called “wet cleaning” or “manual cleaning”) is carried out that releases the process chamber to open air and allows an operator to manually wipe off the inner wall of the process chamber with water or an alcohol. Besides the wiping operation of the inner wall surface of the process chamber, the wet cleaning operation also includes the steps of disassembling and taking out those components inside the process chamber that are made of metals, quartz glass or ceramics, washing the components so taken out or wiping contaminants on the surface, and again assembling the components.
Since the semiconductor processing apparatus uses the reactive gas or reactive plasma as described above, the constituent components inside the process chamber are chemically or thermally damaged and undergo wear or breakage. Therefore, the constituent components inside the process chamber have to be periodically exchanged. The constituent components reaching their service life are exchanged at the time of wet cleaning, for example.
As described above, wet cleaning involves the steps of releasing the process chamber to the atmospheric pressure, conducting the manual cleaning operation, then conducting the re-assembling operation and further conducting evacuation of the process chamber. The cleaning operation needs a long time and lowering of productivity. For these reasons, wet cleaning is conducted in, for example, an unavoidable case where dry cleaning fails to lower the number of adhering particles to the semiconductor substrate to a predetermined value.